29 Technical Interview Questions Tech Firms Ask Internship Candidates

Yesterday, Vault released its Top 50 Internships For 2015. The rankings were calculated using data culled from our latest Internship Experience Survey, which was administered earlier this year to 5,800 interns at 100 internship programs. Survey respondents—which came from a variety of industries, including finance, consulting, energy, consumer products, media, and tech—were asked to rate their programs in five areas. They were also asked to provide sample interview questions they received during the hiring process. To that end, below you'll find several technical questions that tech interns were asked to field during their interviews.

1. How is dynamic memory allocated in memory? How is static memory allocated?

2. Which is more efficient for insertion: a singly linked list or a doubly linked list? Which is more efficient for deletion? Which is more efficient for searching? Explain.

3. How do routers, switches, and hubs differ?

4. Please program a linked list in C.

5. Please implement a power function that takes a base and the power. Do this recursively.

6. What are the three pillars of OOP [Object Oriented Programming]?

7. How does the internet work? Explain it as if you were explaining it to your mother.

8. What is fill factor?

9. Describe a buffer overflow. What is the different between symmetric and asymmetric encryption?

10. Provide an example of a simple SQL statement.

11. Describe (in pseudo code) a program that counts from 1 to 10, prints "foo" if the number is divisible by 2, "bar" if the number is divisible by 5, and "foobar" if the number is divisible by both.

12. What do you know about how a computer works?

13. What is a Coalesce in SQL?

14. Explain database normalization.

15. How does DNS [Domain Name System] work? What are some of the differences between Linux distros?

16. How, with the help of encryption, you can eliminate middleman attack on a network?

17. Please explain the waterfall model.

18. What are the stages of the SDLC [systems development life cycle]?

19. Write a function that takes as input the time (hours and minutes) and outputs the angle between the minute and hour hands.

20. What is a pure virtual function? What is a critical region? What is a mutex? Please show in code proper inheritance of classes and virtual functions.

21. Describe public and private key encryption, and try and catch clauses in Java.

22. What is a static variable?

23. What is the difference between a class and an object?

24. How would you approach the problem of a slow database?

25. Explain a proxy.

26. Describe Java collection classes.

27. What are the benefits of recursion?

28. If you were provided with an ASA configuration, what security settings would you want to see?

29. On a website vulnerable to Cross-Site Request Forgery, what would you recommend to remediate the issue?

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